Методические указания для студентов 2 курса судомеханического факультета заочного отделения (стр. 3 из 10)

Vocabulary

1. supercharging - наддув

2. weight-вес

3. pulse system - импульсная система

4. net increase - чистое увеличение

5. gas turbocharging - газотурбонаддув

6. downward - вниз

7. turbocharger - турбокомпрессор

8. inlet valve - выпускной клапан

9. exhaust valve - выхлопной клапан

10. to occur - происходить

11. scavenging-air receiver - ресивер продувочного воздуха

ВАРИАНТ 5

1. Перепишите следующие предложения, подчеркните в каждом из них глагол-сказуемое, определите его видовременную форму и залог.

1) The Chief Mate is showing the life-boats to the inspector now.

2) The ice-breaker has already conducted the cargo ship" Gotland" to the port.

3) A lot of oil has been spilled near the coast.

4) When pistons are received by us they are carefully checked and measured against their original dimensions.

2. Перепишите следующие предложения , подчеркните Participle I и
Participle II и установите, является ли оно определением, обстоятельством
или частью глагола-сказуемого. Переведите предложения на русский язык.

1) The Convention MARPOL 73/78 was primarily aimed at pollution resulting from routine tanker operation.

2) MARPOL 73/78 requires unscheduled inspection or mandatory annual surveys of ships.

3) The lubricant employed should be of good quality.

4) A centrifugal pump on the turbine shaft is often used to supply oil.

3. Перепишите следующие предложения, подчеркните в каждом из них
модальный глагол или его эквивалент. Переведите на русский язык.

1) Water contamination of lubricating oil on board a ship can seriously damage engine bearings and cause engine failure.

2) The equipment is to be delivered within 12 months.

3) All carbon deposits should be removed from cylinder ports.

4) In turbine design the amount of condenser vacuum must be given due attention.

4. Прочитайте и письменно переведите текст, обращая внимание на
пояснения к тексту.

Turbocharging

In the four-stroke naturally aspirated engine, the air for combustion is drawn in from atmosphere the suction stroke. In the turbocharged engine, the air is supplied pre-compressed and, in some cases, cooled. A greater weight of air for combustion is thus available in the cylinder and due to the valve overlap the cylinder is scavenged of the exhaust gases. The effect of turbocharging is:

1) to increase the weight of air available for combustion,

2) to scavenge the residual gases,

3) to cool all parts in the combustion chamber.

With the greater air weight, a greater quantity of fuel can be burned and an increase of power obtained without increasing the temperature and the heat stresses in the engine.

The turbocharger comprises a single stage axial flow exhaust gas driven turbine, driving a centrifugal air compressor which draws air from the atmosphere and delivers it under pressure to the air inlet manifold, then through the air inlet valves to the cylinders the gas turbine wheel and air impeller are mounted on a common rotor shaft carried in bearings mounted at each end of the shaft.

The impulse energy of the gases from the various cylinders is used to drive the turbocharger and there is no loss of engine power. To ensure efficient scavenging it is necessary to have a large overlap of the air and exhaust valves. With this overlap on multi-cylinder engines it is essential to avoid interference in the exhaust pipes between the exhaust impulses from successive cylinders, as this would interfere with efficient scavenging. To eliminate this, two, three or four exhaust pipes are used depending on the number of cylinders.

Vocabulary

1. naturally aspirated engine - обычный двигатель, без наддува

2. residual exhaust gas - остаточный выхлопной газ

3. throttling - дросселирование

4. valve overlap - перекрытие клапанов

5. exhaust gas driven turbine - турбина, приводимая в движение выхлопными газами

6. multi-cylinder engine - многоцилиндровый двигатель

7. to avoid interference - избегать помехи

8. wheel - рабочее колесо, диск

9. weight - вес, объем

10. turbocharger - турбокомпрессор

11. to scavenge - продувать

12. loss-потеря

ЧАСТЬ 3. РАЗГОВОРНЫЕ ТЕМЫ

1. My Speciality

The principal aim of the shipmechanical faculty is to train certificated specialists in the following fields:

1) shipbuilding,

2) ship power plants,

3) maintenance of ship power plants,

4) technical maintenance of ship and ship equipment,

5) environment engineering protection.

The graduates of the faculty get the specialities of a mechanical engineer, a ship builder and an environment protection engineer.

The educational course begins with mastering mathematics, physics, chemistry, drawing, descriptive geometry. Students also have humanitarian sciences: history of Russia, philosophy, political history, foreign languages, etc. The graduates of the faculty get the speciality of a mechanical engineer.

Junior students study both technical and social sciences. Senior students study special subjects such as details of machines, theory of machines and mechanism, ship internal combustion engines and others.

Special attention is paid to studying fuel system, cooling and lubricating systems. Students study engine arrangement and types of engines. Besides they study turbine arrangement.

III

Each year students of the faculty have an industrial training. After the first year they have one-month industrial training. After the third year students have a ship-board training lasting 6 month. Students keep watch, do work as motormen, help to repair damages of an engine. Traditional students practical training takes place in different ports of Siberian rivers and at the Sea of Japan. Undergraduates collect necessary information for their graduation papers.

The faculty comprises several chairs: such as ship internal combustion engines chair, shipbuilding chair, shiprepairing chair, technology of metals chair and others.

There are some mechanical workshops, labs of internal combustion engines, labs of auxiliary mechanisms, a metal-cutting lab at the disposal of students.

According to the 5-year program the faculty gives fundamental knowledge combined with practical skills.

Vocabulary

1. aim-цель

2. shipmechanical faculty - судомеханический факультет

3. to provide with - обеспечить

4. to solve - решать

5. field - область, отрасль

6. to master - овладевать

7. to combine - сочетать

8. industrial training - производственная практика

9. special attention - особое внимание

10. to devote (to) - уделять

11. fuel system - топливная система

12. cooling system - система охлаждения

13. lubricating system - система смазки

14. engine arrangement - устройство двигателя

15. ship-board training - плавательская практика

16. to last-длиться

17. to keep watch - стоять на вахте

18. to repair - ремонтировать

19. damage - повреждение

20. undergraduate -студент последнего курса

21. graduation paper - диплом

22. to comprise - включать в себя

23. workshop - мастерская

24. at one's disposal - в чём-либо распоряжении

25. auxiliary mechanism - вспомогательный механизм

26. to obtain - получать

27. skills - мастерство, навыки

28. enterprise - предприятие

29. to appreciate - высоко ценить

30. experience - опыт

Questions to be answered:

1. What Academy do you study at?

2. What's the name of your faculty?

3. What's the aim of teaching at the faculty?

4. What subjects do junior and senior students study?

5. What specialities do the graduates from the shipmechanical faculty get?

6. What special subjects are the students taught?

7. Why is special attention devoted to studying cooling, fuel, lubricating systems?

8. What kind of training do the students of the faculty have?

9. How long does a ship-board training last?

10. What do the students do during this training?

11. What chairs does your faculty comprise?

2. Diesel Engine

Diesels are the most economical heat engines. The Diesel engine is an "internal combustion" engine; that is to say, the fuel is burnt inside the engine cylinders and not externally in a separate boiler. The principle of operation is as follows,- a charge of pure air is drawn, or pumped, into the engine cylinder and then compressed by the moving piston to a pressure of about 500 lbs per square inch. When air is compressed, it's temperature rises. Fuel is now sprayed into the engine cylinder, is ignited by the hot air and in burning supplies more heat to the air charge thus causing it to expand and drive the engine piston.

There are two main types of diesels: two-stroke and four- stroke engines.

In two-stroke diesels compression occurs during the first stroke, combustion and expansion occur during the second stroke; exhaust, scavenging and recharging with air occur at the end of the second stroke and at the beginning of the first stroke.

The working cycle of a four-stroke diesel requires four separate strokes of the engine piston to complete the operation. These four strokes are called suction, compression, combustion-expansion and exhaust, but only the third stroke provides the power to drive the ship while the other three require power from the remaining cylinders to perform their various duties. So, what happens during these four cycles?

First stroke: suction

Inlet valve is open, exhaust valve is closed. Air is drawn into the cylinder.

Second stroke: compression

Both valves are closed. Piston compresses the air to high temperature.

Third stroke: combustion- expansion

Fuel injected burns. Temperature and pressure of combustion gases increase. Gas pressure forces the piston down (valves are closed). As the volume available for the gases increases, their pressure and temperature decrease. Piston displacement is used to produce power.

Fourth stroke: exhaust

Exhaust valve is open; inlet valve is closed. Burnt gases are forced out of the engine.

The Diesel Engine is made up of stationary and moving parts.

Stationary parts

These are principally: bedplate, cylinders, cylinder covers and cylinder liners.

Moving parts. These include: piston, connecting-rod, crankshaft, flywheel and valves.

Vocabulary

1.	internal combustion engine	двигатель внутреннего сгорания
2.	to spray	впрыскивать
3.	to ignite	зажигать
4.	charge	(зд.)порция, загрузка, заряд
5.	stroke	ход, такт, длина хода
6.	suction stroke	ход впуска (всасывание)
7.	exhaust stroke	ход выхлопа
8.	compression	сжатие
9.	combustion	сгорание
10.	expansion	расширение
11.	scavenging	продувка
12.	to draw in	втягивать, всасывать
18.	piston	поршень
19.	displacement	перемещение, сдвиг
20.	to force	заставлять, принуждать
21.	to force out	вытеснять, выкачивать
22.	stationary parts	неподвижные части
23.	moving parts	рабочие части

24. bedplate	фундаментная плита
25. crankcase	картер двигателя
26. bearing	подшипник
27. cylinder	цилиндр
28. cylinder covers (heads)		крышки цилиндров
29. liner	втулка, гильза
30. connecting	rod	шатун
31. crankshaft	коленчатый вал
32. flywheel	маховик
33. valve	клапан
34. crank	мотыль 3. Turbines

The turbine is a heat engine consisting of a rotor carrying moving blades, a casing in which the rotor revolves, and stationary nozzles through which the steam is expanded or directed. Glands, bearings, throttle valve, governor and other devices are necessary for operation of the unit.

There are two kinds of turbines: steam turbines and gas turbines.

The steam turbine consists of two principal elements: 1) nozzles, a device for converting some of the thermal energy of the steam into kinetic energy, and 2) moving blades, an arrangement for converting the kinetic energy of the steam into shaftwork.

Steam turbines may be classified as impulse turbines and reaction turbines.

In the impulse turbine the steam expands only through stationary nozzles, dropping in pressure and increasing in velocity. The steam then impinges against the moving blades causing rotation and mechanical work.

In the reaction turbine the stationary nozzles have the same appearance as the moving blades. The steam drops in pressure and at the same time expands while passing through both the stationary nozzles and the moving blades.

Turbines are classed also as: 1) high, 2) intermediate and 3) low pressure.